Digital measurement transmitters are those which include at least one microprocessor for conditioning the measurement signals, or for controlling internal functions. Especially in safety-relevant applications, it is necessary to be able to recognize a malfunctioning of a measurement transmitter, or its components, with a sufficiently high probability. In the NAMUR Recommendation NE43, it is, for example, proposed, that, in the case of measuring devices having a measurement signal current lying in a band range between 4 and 20 mA, a device malfunction be signalled with an error signal current outside of this band range, e.g. not more than 3.6 mA, or, on the other end, at least 21 mA.